Optimizing Astatine-211 Radiolabeling: New Research Highlights the Importance of Timing
Atley Solutions is proud to spotlight the groundbreaking research led by our own Ellinor Hansson, which sheds light on a crucial aspect of astatine-211 (At-211) radiochemistry. Published in Nuclear Medicine and Biology, the study provides key insights into how the timing of radiolabeling significantly impacts radiochemical yield. These findings underscore the advantages of performing radiolabeling as soon as possible after At-211 purification, a process that is fully enabled by the Atley C100 module. Ellinor will present her work at iSRS in Gold Coast, Australia in May 11-15, 2025.
The Challenge of Astatine-211 Radiolabeling
Astatine-211 is a promising radionuclide for targeted alpha therapy, offering a powerful tool for cancer treatment. However, due to its short half-life of just 7.2 hours, maintaining radiochemical yields during drug manufacturing is of paramount importance.
Ellinor Hansson and colleagues investigated how the time elapsed between At-211 purification and radiolabeling influences radiochemical yield. The study demonstrated that the longer At-211 remains in an unbound state after purification, the more significant the yield loss becomes—especially at low precursor concentrations.
Key Findings: Time Matters
The research involved purifying At-211 from irradiated bismuth targets through dry distillation, followed by elution in chloroform. The purified At-211 was then stored either as a dry residue or as a chloroform solution before undergoing radiolabeling at various time points. Two types of labeling reactions were studied: electrophilic astatination and nucleophilic astatination.
Findings showed that there is a negative exponential correlation between the number of alpha decay events (time) occurring whilst At-211 is stored in an unbound state before labeling, and the radiochemical yield of radiolabeling processes, particularly when precursor concentrations were low.
Practical Implications for Radiopharmaceutical Development
The implications of this study are substantial for the development and logistics of At-211-based radiopharmaceuticals:
- Early Radiolabeling for High Yield: To maximize radiochemical yield with high specific activity, radiolabeling should occur as soon as possible after purification.
- Impact on Supply Chain Decisions: The findings suggest that transporting purified At-211 over long distances may not be ideal. Instead, shipping irradiated bismuth targets for local purification and immediate radiolabeling could be a more effective strategy.
The Atley C100 Advantage
The Atley C100 module is designed to streamline the At-211 purification and radiolabeling process, ensuring that radiolabeling can be performed with minimal delay. This research further validates the importance of integrating efficient, on-site radiolabeling
